Standard electrical lines carrying alternating-current electricity in the 220V-400V range emit radiation known as electrosmog that is alleged to be unhealthy. In order to avoid the emission of electrosmog by cables and to keep it from the environment, this emission should be shielded in or on these cable ducts, especially adjustably and adapted to the local demand and in a manner making it easy to retrofit to existing wiring. According to the local needs on different positions of the conduit, different shielding strength are needed.
Electrosmog consists of electric and magnetic fields, originated by electric current in cable conduits, interfering with the environment. Electric fields do not spread themselves far and are easy to shield, however magnetic fields can have deleterious health effects at considerably greater distances.
Cable conduits or rather cable ducts for supplying electric power in buildings are manufactured either from plastic material or from steel or aluminum, for instance cable channels, pipes, hoses, channels. Such cable-guides, usually hold electric wires that are not shielded. These electrical conductors thus emit electrosmog for the following reasons:
1. Cable guides made from plastic do not shield electric and magnetic fields from current-carrying cables.
2. Cable guides made from sheet steel do not shield magnetic fields at a frequency at 50 or 60 Hertz, as is standard in common power supplies; instead only electric fields are shielded. Electrosmog emerges as magnetic fields.
3. Shielded cables for power supply in buildings are rarely installed in cable guides because of their wider diameter and higher costs.
4. In case of cable conduits of plastic or composite plastic material or rubber including shielding substances such as metal fibers, metal-powder, carbon-powder and the like, there is an attenuation of the emerging electrosmog, but at substantial high cost and considerable material thicknesses only.
5. Cable conduits consisting of plastic in composite construction with shielding foils are expensive with cost and material; their shielding factor cannot be varied locally.
Cable conduits in buildings are placed in the wall usually in flexible or rigid tubes, on the wall in form of channels made of plastic, steel or aluminum, below the floor as channels made of plastic or steel and below the ceiling in tray systems.
Unlike electric fields which can be shielded by brickwork as well as by steel or other metals, magnetic fields at a frequency of 50 or 60 Hertz penetrate brickwork and steel as well as plastic material in all directions when the cables in the conduits are not themselves shielded.
Furthermore, the shielding effect of soft magnetic alloys or other alloys with similar features of high permeability are known. Soft magnetic alloys shield electric as well as magnetic fields that originate from current wiring through the whole frequency range. In the contrary steel and aluminum in fact shield electric fields; however show only low or no shielding property for magnetic fields below a frequency of 100 kHz.
According to the current state of the art the shielding factor of already laid or new cable conduit elements cannot be subsequently modified. In case additional shielding is needed, the shielding is not applied at the cable guides, but to the walls or at the appliances to be shielded. Therefore the exposure of humans at least in significant areas of the environment in general remains unhampered.
Standard cable conduits for power supply normally made from plastic or metal are laid along the wall, below the ceiling as well as below the floor. Depending on the mode of installation low frequency as well as high frequency electric and magnetic fields can propagate from these cable conduits and interfere with the environment. Just in buildings for offices, homes, hospitals etc. such cable-conduits are equipped with unshielded cables or wires below the floor, along the wall or below the ceiling. In hospitals with bedrooms as well as offices, cable-conduits in most cases are laid near the human body or in the level of head. Electrosmog therefore can reach and affect persons and appliances from many directions.
As the harmful influence of low frequency electrosmog in that scale for is contended, there is its long-term influence with respect to disorders of sensitivity at electro-sensible persons and damage to patients with implants such as cardiac pacemakers, nervous stimulators, implanted insulin-pumps or hearing aids etc. or their interference liability is evident.
The use of electric and electronic appliances in homes, offices, hospitals increases every year rapidly. People are overburdened by electrosmog, since the unavoidable electrosmog, from monitors, printers, scanners, electro-installations on desks or refrigerators, electric stoves, microwave ovens that add to the permanent electrosmog penetrating unshielded cable conduits.
Therefore not only the influence of single appliances counts on persons as shown in statistics, but also the sum total of all influencing fields, as well as their duration which with regard to electrosmog are emerging from cable guides in various rooms from all directions and which are lasting all the time.